A recent chart from Upjohn Institute's Susan Houseman shows how declines in manufacturing employment in the U.S. are relative to the declines in the number of U.S. factories since the year 2000. Is it related to technology and automation? Or perhaps the price competition from China and other low-cost countries? Either way the question remains, why are some cities not only surviving, but thriving in an otherwise obvious downturn? Economist Tim Bartik may have the answer.